US9382161B2ActiveUtilityA1

Process using non-fired refractory products as a lining of large-volume industrial furnaces and industrial furnaces lined with the non-fired refractory products

74
Assignee: REFRATECHNIK HOLDING GMBHPriority: Nov 29, 2012Filed: May 30, 2014Granted: Jul 5, 2016
Est. expiryNov 29, 2032(~6.4 yrs left)· nominal 20-yr term from priority
Inventors:Bernd ScheubelHelge JansenHans-Jurgen KlischatRolf-Dieter KizioHolger Wirsing
C04B 35/101C04B 35/043C04B 35/0435C04B 33/1305C04B 35/047C04B 35/057C04B 35/103C04B 35/20C04B 2235/5436C04B 35/6303C04B 33/131C04B 2235/5427C04B 35/06F27D 1/0006C04B 2235/3206C04B 35/443C04B 2235/721C04B 35/565C04B 35/634C04B 35/6316C04B 35/66C04B 2235/321C04B 33/1315C04B 35/6365C04B 33/04F23M 2900/05004C04B 35/632C04B 35/6306Y10T156/1089C04B 2235/604C04B 35/42C04B 35/18F23M 5/00C04B 2235/96C04B 35/63496C04B 2235/3246C04B 35/44F27B 7/28
74
PatentIndex Score
4
Cited by
34
References
50
Claims

Abstract

There is a process for creating graphite free non-fired refractory products, which are molded using presses and which includes using a plurality of different binders. The binders comprise a first binder for binding grains of granulation between room temperature and 400° C., a second binder binding the grains of granulation between 300 and 900° C.; and a third binder binding granulations of the refractory materials that enter into ceramic binding at temperatures above 900° C. This process is for producing at least one of magnesia chromite bricks, magnesia spinel and spinel bricks, magnesia zirconia and magnesia zircon bricks, magnesia hercynite and magnesia galaxite bricks, dolomite, dolomite-magnesia, and lime bricks, forsterite and olivine bricks, magnesia forsterite bricks, magnesia pleonast bricks, magnesia bricks. These products are configured to operate as a fire-side, refractory lining of large-volume industrial furnaces operated with an essentially oxidizing atmosphere, for the production of cement, lime, magnesia, and doloma.

Claims

exact text as granted — not AI-modified
The invention claimed is: 
     
       1. A process for the production of refractory linings of large-volume industrial furnaces operated with an oxidizing or essentially oxidizing atmosphere in which cement, lime, magnesia, or doloma is produced, comprises the following steps:
 lining a fire-side of the industrial furnaces with non-fired graphite free refractory products in the form of pressed bricks containing binders and granulations in each case of refractory raw materials entering into ceramic binding at temperatures above 900° C., whereby the refractory raw materials are in each case the same known raw materials from which usually the following fired brick types are produced 
 magnesia chromite bricks, 
 or 
 magnesia spinel and spinel bricks, 
 or 
 magnesia zirconia and magnesia zircon bricks, 
 or 
 magnesia hercynite and magnesia galaxite bricks, 
 or 
 dolomite, dolomite-magnesia, and lime bricks, 
 or 
 forsterite and olivine bricks, 
 or 
 magnesia forsterite bricks, 
 or 
 magnesia pleonast bricks, 
 or 
 magnesia bricks, 
 whereby the products contain at least a first temporary binder that guarantees binding of the grains of the granulation in a temperature range between room temperature and 500° C., and at least a second temporary binder that guarantees binding of the grains of the granulation in the temperature range between 300 and 1000° C., and 
 whereby the pressed bricks have a cold pressure strength above 20 MPa. 
 
     
     
       2. The process according to  claim 1 , wherein the refractory raw materials enter into ceramic binding at temperatures above 1000° C. 
     
     
       3. The process according to  claim 1 , wherein the first temporary binder that guarantees binding of the grains of the granulation in a temperature range between room temperature and 400° C. 
     
     
       4. The process according to  claim 1 , wherein the second temporary binder that guarantees binding of the grains of the granulation in the temperature range between 400 and 900° C. 
     
     
       5. The process according to  claim 1 , wherein the bricks have a cold pressure strength between 30 and 130 MPa. 
     
     
       6. The process according to  claim 1 , wherein the bricks have a cold pressure strength between 40 and 120 MPa. 
     
     
       7. The process according to  claim 1 , wherein the granulations have a grain distribution according to Litzow, Fuller or Furnas. 
     
     
       8. The process according to  claim 1 , wherein the products have usual brick formats and have been pressed with pressing pressures between 50 and 250 MPa. 
     
     
       9. The process according to  claim 8 , wherein the bricks have been pressed with pressing pressures between 80 and 200 MPa. 
     
     
       10. The process according to  claim 1 , wherein the products are treated before use at temperatures between 90 and 400° C., to liquid contents below 0.8 wt.-%. 
     
     
       11. The process according to  claim 10 , wherein the products are treated before use at temperatures between 100 and 350° C. 
     
     
       12. The process according to  claim 10 , wherein the products are treated to liquid contents below 0.5 wt.-%. 
     
     
       13. The process according to  claim 1 , wherein the products are tempered in temperature ranges below 1000° C., before use or in situ. 
     
     
       14. The process according to  claim 13 , wherein the products are tempered in temperature ranges between 200 and 800° C., before use or in situ. 
     
     
       15. The process according to  claim 1 , wherein a binder from the following group is contained as a first temporary binder:
 lignin sulfonate, synthetic resin, tar, pitch, novolac, dextrin, organic acids, polyvinyl alcohol, gum arabic, saccharide preparations, as well as mixtures thereof. 
 
     
     
       16. The process according to  claim 15 , wherein the first temporary binder also contains phosphoric acid and/or phosphates and, in this connection, in the case of a powder additive, with fineness values <150 μm. 
     
     
       17. The process according to  claim 16 , wherein the first temporary binder contains the phosphoric acid and/or phosphates as a liquid in amounts between 0.5 and 8 wt.-% with reference to the dry material or the dry mixture of refractory materials. 
     
     
       18. The process according to  claim 16 , wherein the powder additive has a fineness value of <90 μm. 
     
     
       19. The process according to  claim 1 , wherein at least one binder from the following group is contained as a second temporary binder:
 Al, Mg, Si, Fe and their alloys, SiC, B 4 C, Si 3 N 4 , AlN, BN, sialon, fine-grained mineral materials, spinel, alumina, zircon oxide, silicon dioxide, calcium aluminates, aluminum silicates and clays, compounds containing iron. 
 
     
     
       20. The process according to  claim 19 , wherein the secondary temporary binder is selected from the group consisting of MgO, micro-silica, and compounds containing iron oxide. 
     
     
       21. The process according to  claim 20 , wherein the compounds containing iron oxide are selected from the group consisting of magnetite, hematite, goethite, limonite, and siderite. 
     
     
       22. The process according to  claim 19 , wherein the secondary temporary binder is in amounts between 0.5 and 15%, with reference to the dry material or the dry mixture of refractory materials, and, in this connection with fineness values <150 μm. 
     
     
       23. The process according to  claim 22 , wherein the secondary binder is contained in amounts between 1 and 4%. 
     
     
       24. The process according to  claim 23 , wherein the fineness values are <90 μm. 
     
     
       25. The process according to  claim 15 , wherein the organic acids are selected from the group consisting of citric acid, malic acid, and acetic acid). 
     
     
       26. A process for the production of refractory linings of large-volume industrial furnaces operated with an oxidizing or essentially oxidizing atmosphere in which cement, lime, magnesia, or doloma is produced, comprises the following steps:
 lining a fire-side of the industrial furnaces with non-fired graphite free refractory products in the form of pressed bricks containing binders and granulations in each case of refractory raw materials entering into ceramic binding at temperatures above 900° C., whereby the refractory raw materials are in each case the same known raw materials from which usually the following fired brick types are produced: 
 chamotte bricks, 
 or 
 bricks on the basis of SiC+andalusite, 
 or 
 bricks on the basis of SiC+kaolin, 
 or 
 bricks on the basis of bauxite, 
 or 
 bricks on the basis of bauxite+SiC, 
 or 
 bricks on the basis of andalusite, 
 or 
 bricks on the basis of mullite, 
 or 
 bricks on the basis of mullite+SiC, 
 whereby the products contain at least a first temporary binder that guarantees binding of the grains of the granulation in a temperature range between room temperature and 500° C., and at least a second temporary binder that guarantees binding of the grains of the granulation in the temperature range between 300 and 1000° C., and 
 whereby the pressed bricks have a cold pressure strength above 20 MPa. 
 
     
     
       27. The process according to  claim 26 , wherein the refractory raw materials enter into ceramic binding at temperatures above 1000° C. 
     
     
       28. The process according to  claim 26 , wherein the first temporary binder guarantees binding of the grains of the granulation in a temperature range between room temperature and 400° C. 
     
     
       29. The process according to  claim 26 , wherein the second temporary binder guarantees binding of the grains of the granulation in the temperature range between 400 and 900° C. 
     
     
       30. The process according to  claim 26 , wherein the bricks have a cold pressure strength between 30 and 130 MPa. 
     
     
       31. The process according to  claim 26 , wherein the bricks have a cold pressure strength between 40 and 120 MPa. 
     
     
       32. The process according to  claim 26 , wherein the granulations have a grain distribution according to Litzow, Fuller or Furnas. 
     
     
       33. The process according to  claim 26  the products have usual brick formats and have been pressed with pressing pressures between 50 and 250 MPa. 
     
     
       34. The process according to  claim 33 , wherein the bricks have been pressed with pressing pressures between 80 and 200 MPa. 
     
     
       35. The process according to  claim 26 , wherein the products are treated before use at temperatures between 90 and 400° C. 
     
     
       36. The process according to  claim 35 , wherein the products are treated before use at temperatures between 100 and 350° C. 
     
     
       37. The process according to  claim 35 , wherein the products are treated to liquid contents below 0.5 wt.-%. 
     
     
       38. The process according to  claim 26 , the products are tempered in temperature ranges below 1000° C., before use or in situ. 
     
     
       39. The process according to  claim 38 , wherein the products are tempered in temperature ranges between 200 and 800° C., before use or in situ. 
     
     
       40. The process according to  claim 26 , wherein a binder from the following group is contained as a first temporary binder:
 lignin sulfonate, synthetic resin, tar, pitch, novolac, dextrin, organic acids polyvinyl alcohol, gum arabic, saccharide preparations, as well as mixtures thereof. 
 
     
     
       41. The process according to  claim 40 , wherein the organic acids are selected from the group consisting of citric acid, malic acid, and acetic acid. 
     
     
       42. The process according to  claim 40 , wherein the first temporary binder also contains phosphoric acid and/or phosphates and, in this connection, in the case of a powder additive, with fineness values <150 μm. 
     
     
       43. The process according to  claim 42 , wherein the first temporary binder contains the phosphoric acid and/or phosphates as a liquid in amounts between 0.5 and 8 wt.-% with reference to the dry material or the dry mixture of refractory materials. 
     
     
       44. The process according  claim 42 , wherein the powder additive has a fineness value of <90 μm. 
     
     
       45. The process according to  claim 26 , wherein at least one binder from the following group is contained as a second temporary binder:
 Al, Mg, Si, Fe and their alloys, SiC, B 4 C, Si 3 N 4 , AlN, BN, sialon, fine-grained mineral materials, spinel, alumina, zircon oxide, silicon dioxide, calcium aluminates, aluminum silicates and clays, compounds containing iron. 
 
     
     
       46. The process according to  claim 45 , wherein the secondary temporary binder is selected from the group consisting of MgO, micro-silica, and compounds containing iron oxide. 
     
     
       47. The process according to  claim 46 , wherein the compounds containing iron oxide are selected from the group consisting of magnetite, hematite, goethite, limonite, and siderite. 
     
     
       48. The process according to  claim 45 , wherein the secondary temporary binder is in amounts between 0.5 and 15%, with reference to the dry material or the dry mixture of refractory materials, and, in this connection with fineness values <150 μm. 
     
     
       49. The process according to  claim 48 , wherein the secondary binder is contained in amounts between 1 and 4%. 
     
     
       50. The process according to  claim 49 , wherein the fineness values are <90 μm.

Cited by (0)

No later patents cite this yet.

References (0)

No backward citations on record.